EP2715862B1 - Battery for a vehicle, and method for producing a battery - Google Patents

Description

The invention relates to a battery for a vehicle, wherein a plurality of battery cells is arranged in a housing of the battery. The battery includes cooling means for removing heat from the battery cells. In a space provided between the housing and the cooling device, a material is introduced, which assumes a first volume in a ground state and an expanded volume in relation to the first volume in an expanded state. The cooling device is pressed by the spent in its expanded state material against the battery cells. Furthermore, the invention relates to a method for manufacturing such a battery.

The DE 10 2007 010 745 A1 describes a battery for a vehicle with a plurality of battery cells, which are arranged in a battery case. On the battery cells, a heat conducting plate with cooling channels for a heat conducting medium is arranged on the top side. Between cell connectors and the heat conduction plate, a thermally conductive foam, such as a polyurethane foam is disposed. This material fills gaps in the battery case and also ensures that the cooling plate is acted upon by a pressure acting in the direction of the battery cells.

Also at the DE 10 2007 010 739 A1 For example, battery cells of a battery for a vehicle are arranged in a housing, and a heat conduction plate with cooling channels is arranged on the battery cells on the head side. Again, any gaps in the housing of the battery, in particular a gap between above the heat conducting plate arranged cell connectors and the heat conducting plate filled with a potting compound in the form of a heat-conductive polyurethane foam.

The DE 10 2008 059 097 A1 also describes a battery for a vehicle having a plurality of battery cells disposed in a battery case, wherein between a battery housing cover and a top side mounted on the battery cells cooling plate as a protective layer is provided a potting compound, which is formed for example of a foam. However, here the cooling plate is not pressed by expanding the potting compound against the battery cells, as a battery cells comprehensive cell composite is placed in the battery case cover upside down and then the battery case lid is sufficiently filled with potting compound. The potting compound is thus filled in the open housing.

The US 2007/0259258 A1 describes a battery for a vehicle having a plurality of battery cells in a housing, wherein the respective battery cells in the housing with cooling plates in abutment, which partially pass through the housing wall. In the closed housing, a foam, for example, a two-component polyurethane foam is introduced via openings.

The DE 10 2008 059 953 A1 describes a battery for a vehicle with a cooling plate having channels for a cooling fluid. On the cooling plate are battery cells, and the battery cells and the cooling plate are clamped together by a clamping band. Between an arranged under the clamping band clamping plate and an opposite end of the cooling plate of the battery cells, an elastic element, for example, a foam mat or a plurality of springs is arranged. This elastic element presses the battery cells against the cooling plate.

The DE 10 2007 021 293 A1 describes a battery for an electric vehicle, fuel cell vehicle or hybrid vehicle. Individual battery cells, which are combined to form a cell package, are surrounded on the outside by a common housing made of plastic. The housing comprises a container open on one side and a lid closing the container, both of which are manufactured by injection molding. To ensure that the battery cells are fixed in a fixed position and without play in the housing, positioning projections are provided on the bottom and on the lid of the housing, which have areas with different elasticity. The softer region of a respective positioning projection makes it possible to compensate for manufacturing tolerances of the battery cells. For cooling the battery cells tubes are provided in the housing, which are acted upon by a cooling fluid. There are many thin lamellas on the tubes attached, which serve to dissipate heat from the battery cells. The fins are adapted in shape to the respective battery cell, wherein a respective battery cell is accommodated in a receiving space, which is formed by one or more fins.

The DE 10 2009 004 543 A1 describes a vehicle battery with round cells, which are arranged between two radiator walls. Cooling channels for a coolant are provided in the cooler walls. Profile elements made of a thermally conductive material are provided between the battery cells, so that a heat transfer between the round cells is made possible via the profile elements. Clamping devices clamp the two radiator walls together so that they are pressed with comparatively great force against the profile parts and the round cells.

The EP 2 065 963 A2 describes a battery for a vehicle in which a plurality of battery cells form a battery pack. A cooling plate is in thermal contact with a bottom of the battery pack. The cooling plate has a cavity in which cooling tubes are arranged. The cuboid cooling plate with the cavity includes a top wall which is in abutment with the bottom of the battery pack. The expansion of a plastic foam introduced into the cavity causes the cooling tubes to come into intimate contact with the upper wall of the cooling plate.

In these known from the prior art batteries, it is relatively expensive to bring the cooling device in a good heat conducting contact with the battery cells.

Object of the present invention is therefore to provide a battery of the type mentioned above and a method for manufacturing such a battery, which is provided in a particularly simple manner for a good heat dissipation in the cooling mode.

This object is achieved by a battery having the features of patent claim 1 and by a method having the features of patent claim 7. Advantageous embodiments with expedient developments of the invention are specified in the dependent claims.

In the battery according to the invention, a material is introduced between the housing and the cooling device, which in a ground state a first volume and in an expanded state occupies an over the first volume enlarged volume. By the material spent in its expanded state, the cooling device is pressed against the battery cells. By means of such material, which can also be designated as an expansion medium, a particularly good contact of the cooling device with the battery cells can be achieved. This in turn results in the operation of the cooling device to a particularly good dissipation of the heat released by the battery cells.

The introduction of the expansion agent in a space provided between the housing and the cooling device gap is also particularly easy to accomplish, so that the battery can be produced particularly low expenditure. The increase in volume of the expansion medium occurring after introduction between the housing and the cooling device ensures a high contact pressure with which the cooling device is brought into contact with the battery cells.

Here, at least one wall of the housing of the battery is formed by separators, which electrically isolate the battery cells from each other. If the separators provided for potential isolation at the same time form the housing of the battery, the battery can be manufactured particularly easily. The separators can in this case in particular be connected to one another such that the at least one wall of the housing is hermetically sealed against water and / or moisture, in particular atmospheric moisture. This can be ensured for example by gluing the separators together.

In addition, according to the invention, at least one receiving space for the cooling device is formed by the at least one wall. Then, in the production of the battery, the cooling device need only be introduced into the receiving space formed by mounting the separators. Then then introduced into the receiving space expansion means ensures that the cooling device is pressed with a correspondingly large contact pressure against the battery cells.

In an advantageous embodiment of the invention, the material is designed as unyielding foam in its expanded and cured state. Such a foam, such as in the form of a mounting foam, can be particularly easily introduced between the housing and the cooling device become. The mounting foam, for example, as a one-component mounting foam or as a two-component mounting foam inexpensive to deploy and easy to handle.

The cooling device preferably comprises at least one profile part through which a coolant can flow. Such a profile part can be formed particularly easily and inexpensively by extrusion, and during operation of the cooling device, the coolant ensures a particularly efficient heat dissipation.

It has been found to be advantageous if between the at least one profile part and a shell of the respective battery cell thermal compound is arranged. As a result, manufacturing tolerances of the battery cells and / or the cooling device and / or the housing can be compensated particularly well. The thermal compound also ensures a surface contact of the cooling device to the battery cells and prevents the occurrence of thermally insulating air between the shell of the battery cells and the cooling device.

Additionally or alternatively, a thermally conductive adhesive between the profile part and the sheaths of the battery cells may be arranged. Then a particularly good heat transfer from the battery cells to the cooling medium is ensured not only in cooling mode, but also a particularly secure hold of the profile parts on the sheaths of the battery cells.

In a further advantageous embodiment, the at least one profile part is formed from an aluminum alloy. This material ensures a particularly good heat transfer from the battery cells to the coolant. In addition, a profile part of an aluminum alloy of an advantageously low weight.

The profile part can also be formed from a non-destructive bendable plastic. It is also possible for at least one profile part made of an aluminum alloy and at least one profile part made of a plastic to be used in the battery. If the battery has a profile part made of non-destructively deformable, in particular elastic, plastic, so the risk of damage to the profile part in an accidental application of force to the battery is particularly low. So it can be accident-related Applying force to a displacement of the battery cells relative to the cooling device come without the profile part kinks or breaks. As a result, leakage of the coolant from the cooling device can be particularly largely prevented.

In addition, the use of plastic for the profile part results in a more uniform heat dissipation over the entire battery due to the lower compared to metal heat transfer coefficient. In the case of a profile part with a large heat transfer coefficient, in fact the coolant is already heated comparatively strongly by the upstream battery cells, so that a lower current is then applied to the downstream battery cells. Temperature difference between the coolant and the battery cells and thus less efficient heat dissipation is given.

In the method for manufacturing a battery for a vehicle according to the invention, a plurality of battery cells are arranged in a housing of the battery. In addition, a cooling device designed to dissipate heat from the battery cells is arranged in the housing. Subsequently, a material is introduced into a space provided between the housing and the cooling device, whereby the cooling device is pressed against the battery cells by an increase in the volume of the material.

At least one wall of the housing of the battery is formed by separators, which electrically insulate the battery cells from each other. By at least one wall at least one receiving space for the cooling device is formed, in which the cooling device is introduced. By such brought into contact with the battery cells cooling device can be achieved in cooling operation, a particularly efficient dissipation of heat of the battery lines.

The advantages and preferred embodiments described for the battery according to the invention also apply to the method according to the invention for manufacturing a battery.

The features and combinations of features mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures are not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the invention.

Fig. 1

eine Perspektivansicht einer Batterie zum Speichern und Freigeben von Antriebsenergie für ein Fahrzeug;

Fig. 2

in einer Perspektivansicht einen Separator, welcher zwei Batteriezellen der Batterie elektrisch voneinander isoliert;

Fig. 3

eine Schnittansicht durch die Batterie gemäß Fig. 1;

Fig. 4

einen Deckel der Batterie in einer Ansicht von unten, welcher ein durch die Separatoren gebildetes Gehäuse für die Batteriezellen nach oben hin abschließt;

Fig. 5

den Deckel gemäß Fig. 4 in einer Draufsicht; und

Fig. 6

ausschnittsweise die Batterie gemäß Fig. 1 in einer weiteren Schnittansicht.

Further advantages, features and details of the invention will become apparent from the claims, the following description of preferred embodiments and from the drawings. Showing:

Fig. 1

a perspective view of a battery for storing and releasing drive power for a vehicle;

Fig. 2

in a perspective view of a separator, which electrically isolates two battery cells of the battery from each other;

Fig. 3

a sectional view through the battery according to Fig. 1 ;

Fig. 4

a lid of the battery in a view from below, which closes a housing formed by the separators for the battery cells at the top;

Fig. 5

the lid according to Fig. 4 in a plan view; and

Fig. 6

in sections, the battery according to Fig. 1 in a further sectional view.

An in Fig. 1 shown battery 10 for a vehicle is formed for example as a lithium-ion battery. The battery 10 comprises a plurality of battery cells 12, which are electrically insulated from one another by separators 14 formed from a plastic, which are also referred to as spacers (cf. Fig. 6 ). The present prismatic battery cells 12 form a stack.

The separators 14, which are joined together by gluing, form side walls 16 and a bottom plate 18 (see FIG. Fig. 2 ) of a housing of the battery 10, in which the stack of the battery cells 12 is accommodated. In the area of the bottom plate 18 of the housing formed by the separators 14, two passages 20 are formed by the separators 14 (see FIG. Fig. 2 ), in which two profile parts 22, 24 of a cooling device are received (see. Fig. 1 ).

The profile parts 22, 24 are formed as a flat tube through which a coolant can flow, in which a plurality of mutually parallel cooling channels are formed by ribs 26 (cf. Fig. 3 ). At a first of the profile parts 22, a coolant connection 28 is arranged, via which the coolant is supplied to the profile part 22. A coolant connection 30 provided on the second profile part 24 serves to lead the heated coolant away from the battery 10 to a cooler (not shown).

In particular from Fig. 3 It can be seen that a height of the profile parts 22, 24 is slightly less than a height of the profile parts 22, 24 receiving passages 20. In a space between the bottom plate 18 formed by the separators 14 and the profile parts 22, 24 is in the region of the passages 20 arranged a mounting foam 32.

The mounting foam 32 is introduced into the passages 20 in the production of the battery 10 after the introduction of the profile parts 22, 24 in the passages 20. As a result of the increase in volume of the mounting foam 32 resulting from the expansion of the mounting foam 32, the latter ensures that the profile parts 22, 24 are pressed against the sheaths of the battery cells 12 with a high contact pressure. The expanded, cured mounting foam 32 ensures that the large contact force is permanently maintained.

For tolerance compensation and to ensure a particularly good, areal heat transfer between the profile parts 22, 24 and the battery cells 12, a layer of thermal compound 34 is also provided between the profile parts 22, 24 and the battery cells 12.

The profile parts 22, 24 may be formed of an aluminum alloy. Alternatively, the profile parts 22, 24 may be formed of a flexible, non-destructively bendable plastic, so that even with an accidental force application of the battery 10, the profile parts 22, 24 do not kink or break and there is no leakage of coolant from the profile parts 22, 24.

When using plastic for the profile parts 22, 24 is also given a particularly uniform heat dissipation from the battery cells 12, because due to the comparatively low heat transfer coefficient of plastic not already from the - seen in the flow direction of the coolant through the coolant port 28 - upstream arranged battery cells 12th a large heat input into the coolant takes place.

The housing for the stack of battery cells 12 is formed by the separators 14 arranged between each two battery cells 12 and two separators 36 terminating the end of the stack of battery cells 12 (cf. Fig. 1 ). The separators 14, 36 formed from an inherently rigid plastic are glued together in respective contact areas 38 (cf. Fig. 6 ).

In addition, provide in the investment areas 38 provided positive engagement elements, for example in Fig. 3 shown cones 40, and with these corresponding recesses in the separators 14, 36 for a correct position arrangement of the separators 14, 36 to each other. The adhesively bonded separators 14, 36 form a stack of the battery cells 12 to five sides hermetically sealed housing, and a cover 42 (see. Fig. 4 ) closes the housing at the top against water and moisture from tight.

The cohesion of the housing is ensured by side plates 44 and end plates 46 (see. Fig. 1 ), which surround the housing on the outer peripheral side. In this case, tongues 48 formed on the end plates 46, formed in particular of a spring steel, are inserted into corresponding lugs provided in the side plates 44. Another fixing plate 48 extends on the bottom side and between the two profile parts 22, 24 of the in Fig. 1 front end plate 46 to the rear end plate and is also fixed to the end plates 46.

The assembled separators 14 form guide rails 50 for provided on the lid 42 locking lugs 52 (see. Fig. 3 ). The locking lugs 52 are glued in the guide rails 50 with an elastic and sealing adhesive (see. Fig. 4 ). Thus, the housing for the stack of battery cells 12 is also tight at the top.

With the separators 14 integrally dome 54 or sockets are formed, which pass through corresponding passage openings in the side plates 44 and in the fixing plate 48 (see. Fig. 3 ). Thus, the side plates 44 and the fixing plate 48 ensure that predetermined distances between the separators 14 are maintained (cf. Fig. 1 ). The dome 54 are hot staked after the introduction of the same in the passage openings in order to achieve a secure support of the side plates 44 and the fixing plate 48.

In the lid 42 busbars 56 are integrated, via which poles of the battery cells 12 are electrically contacted. For this purpose, the busbars 56 by screws 58 (see. Fig. 3 ) are connected to the poles of the battery cells 12. Alternatively, it is possible to weld the bus bars 56 to the poles of the battery cells 12. A cover 60, which is sealed by a seal 62 against a base of the cover 42, ensures that the screws 58 and the bus bars 52 are protected upwardly against ingress of moisture or water.

Furthermore, lines 64, via which the voltage of the battery cells 12 is detected, are integrated in the cover 42. In addition, in the lid 42 a Channel 66 is provided, through which in case of failure from the battery cells 12 leaking hot gases are discharged. By means of two high-voltage connections 68 integrated in the cover 42, electrical energy for a drive motor of the vehicle can be taken from the battery 10 or introduced into the battery 10.

In a region of the lid 42 in which an end formed as a contact tongue of the high-voltage terminal 68 is arranged, a sealing potting compound 76 may be provided (see. Fig. 6 ). A provided in the lid 42 board 70 (see. Fig. 5 ) is also covered in the battery 10 by a cover 72 (see. Fig. 1 ).

How out Fig. 6 it can be seen, the coolant connection 30 is connected in a sealing manner via a sealing ring 74 arranged in the end-side separator 36 to the profile part 24 assigned to this coolant connection 30. The connection of the second coolant port 28 to the associated profile part 22 takes place in an analogous manner.

Claims (7)

1. Battery for a vehicle, comprising a plurality of battery cells (12) arranged in a housing (16, 18, 20) of the battery (10), and having a cooling device (22, 24) for removing heat from the battery cells (12),
   wherein a material (32) is introduced into a gap provided between the housing (20) and the cooling device (22, 24), said material, in a basic state, having a first volume and, in an expanded state, having a volume which is greater than the first volume, the cooling device (22, 24) being pressed against the battery cells (12) by the material (32) which has been converted into its expanded state, characterised in that
   at least one wall (18) of the housing of the battery (10) is formed by separators (14, 36) which electrically insulate the battery cells (12) from one another, while at least one receiving space (20) for the cooling device (22, 24) is formed by the at least one wall (18).
2. Battery according to claim 1,
   characterised in that
   the material is embodied as a foam material (32) which is rigid in its expanded and hardened state.
3. Battery according to claim 1 or 2,
   characterised in that
   the cooling device comprises at least one profile part (22, 24) through which a coolant is able to flow.
4. Battery according to claim 3,
   characterised in that
   heat-conducting paste (34) and/or a heat-conducting adhesive is arranged between the at least one profile part (22, 24) and a casing of the respective battery cell (12).
5. Battery according to claim 3 or 4,
   characterised in that
   the at least one profile part (22, 24) is formed from an aluminium alloy.
6. Battery according to one of claims 3 to 5,
   characterised in that
   the at least one profile part (22, 24) is formed from a plastics material that can be non-destructively flexed.
7. Method for producing a battery (10) for a vehicle, wherein a plurality of battery cells (12) are arranged in a housing (16, 18, 20) of the battery (10), and wherein a cooling device (22, 24) designed to remove heat from the battery cells (12) is arranged in the housing (16, 18, 20),
   wherein a material (32) is introduced into a gap provided between the housing (20) and the cooling device (22, 24), the cooling device (22, 24) being pressed against the battery cells (12) by an increase in the volume of the material (32), characterised in that
   at least one wall (18) of the housing of the battery (10) is formed by separators (14, 36) which electrically insulate the battery cells (12) from one another, while at least one receiving space (20) for the cooling device (22, 24), into which the cooling device (22, 24) is placed, is formed by the at least one wall (18).

Images